Shewanella oneidensis MR-1 in situ biosynthesis of Ag nanoparticles on TiO2 nanotubes with enhanced photocatalytic performance

Abstract

Biogenetic nanocomposites research provides valuable methods for the green synthesis of nanomaterials. As a dissimilatory metal-reducing bacterium, Shewanella oneidensis MR-1 is used to reduce Ag+ to Ag nanoparticles (Ag NPs) (diameter about 10 nm) under anaerobic conditions, resulting in the in-situ formation of Ag NPs immobilised on TiO2 nanotubes (TNTs) (Ag/TNTs nanocomposites). The loading amount of Ag nanocrystals on the TNT surface can be controlled easily through adjusting the AgNO3 concentration and further influence visible-light absorption efficiency of Ag/TNTs nanocomposites by decreasing the Ag loading amount. Ag/TNTs nanocomposites show superior photocatalytic efficiency under simulated sunlight than single TiO2 nanomaterials. Moreover, the photocatalytic capacity of Ag/TNTs nanocomposites synergistic by S. oneidensis MR-1 is further enhanced and the degradation ratio of methylene blue reaches 92.3% within 30 min which attributed to a synergistic effect.